1. Field of the Disclosure
The disclosure relates generally to apparatus and methods for control of fluid flow from subterranean formations into a production string in a wellbore.
2. Description of the Related Art
Hydrocarbons such as oil and gas are recovered from a subterranean formation using a well or wellbore drilled into a formation. In some cases the wellbore is completed by placing a casing along the wellbore length and perforating the casing adjacent each production zone (hydrocarbon bearing zone) to extract fluids (such as oil and gas) from such a production zone. In other cases, the wellbore may be open hole, and in a particular case may be used for injection of steam or other substances into a geological formation. One or more inflow control devices are placed in the wellbore to control the flow of fluids into the wellbore. These flow control devices and production zones are generally separated from each other by installing a packer between them. Fluid from each production zone entering the wellbore is drawn into a tubular that runs to the surface. It is desirable to have a substantially even flow of fluid along the production zone. Uneven drainage may result in undesirable conditions such as invasion of a gas cone or water cone. In the instance of an oil-producing well, for example, a gas cone may cause an in-flow of gas into the wellbore that could significantly reduce oil production. In like fashion, a water cone may cause an in-flow of water into the oil production flow that reduces the amount and quality of the produced oil.
Horizontal wellbores are often drilled into a production zone to extract fluid therefrom. Several inflow control devices are placed spaced apart along such a wellbore to drain formation fluid. Formation fluid often contains a layer of oil, a layer of water below the oil and a layer of gas above the oil. A horizontal wellbore is typically placed above the water layer. The boundary layers of oil, water and gas may not be even along the entire length of the horizontal wellbore. Also, certain properties of the formation, such as porosity and permeability, may not be the same along the horizontal wellbore length. Therefore, fluid between the formation and the wellbore may not flow evenly through the inflow control devices. For production wellbores, it is desirable to have a relatively even flow of the production fluid into the wellbore. To produce optimal flow of hydrocarbons from a wellbore, production zones may utilize flow control devices with differing flow characteristics. Active flow control devices have been used to control the fluid from the formation into the wellbores. Such devices are relatively expensive and include moving parts, which require maintenance and may not be very reliable over the life of the wellbore. Passive flow control, which typically do not have moving parts, are used in the wellbore to control the flow if the fluids into the wellbore. Such devices are configured to flow the fluid axially along the device. The axial inflow can limit the flow of the fluid due to the limited surface area for axial inflow passages. Also, such passive devices are serially placed relative to sand screens, which are used to inhibit flow of solid particles into the wellbore. Such serial combination requires long combined devices.
The present disclosure provides apparatus and method for controlling flow of fluid between a wellbore and a formation that addresses some of the above-noted deficiencies of the inflow control devices.